Among drives for recording/reproducing data on/from optical discs, some drives applicable to CD-R discs or CD-RW discs (hereinafter, abbreviated as “discs”) adopt a Disc At Once recording method as their recording methods.
When a CD-R/RW drive (hereinafter, abbreviated as “drive”) records data transmitted from a host computer by the Disc At Once recording method, the drive initially records data in a lead-in area of an optical disc, then records data in at least one track, and finally records data in a lead-out area. This recording process must be performed at a time and without interruption from the lead-in area through the track to the lead-out area.
Further, a CD duplication system for recording data simultaneously on plural optical discs is constituted by 2 to 10 drives and a control unit for controlling recording and reproduction of these drives.
In this system, the Disc At Once recording process must be carried out simultaneously in all the drives so that one piece of original data is simultaneously recorded on the plural discs by the plural drives.
In this Disc At Once recording method, the drive cannot stop the recording operation for the disc in the middle. Therefore, when the rate of data transfer from the host computers is low, there are cases where buffer under-run occurs and transfer data are broken in process of recording, whereby the recording operation is suspended. At this time, TOC (Table Of Contents) data as an information list of data is already recorded in the lead-in area of the disc. The state of the TOC data and the state of track data in which the transfer data has been broken in process of recording are different from each other, resulting in an improper disc, whereby the data reproduction therefrom becomes impossible.
Further, the CD duplication system has following problems.
In the case of CD-R/RW discs, start time of the lead-in area (hereinafter, referred to as “lead-in area start time”) is changed so as to identify the type of the disc. The numeric value of this lead-in area start time is previously recorded on the disc as ATIP (Absolute Time in Pre-groove) data which is information indicating time and other properties of the disc. For example, there are a disc with the lead-in area start time of 97:24:01 and a disc with the lead-in area start time of 97:34:21. The length of the lead-in area of the former disc is 97:24:01 to 99:59:74 and the length of the lead-in area of the latter is 97:34:21 to 99:59:74. The discs having the different lead-in area start times have different lengths of the lead-in areas, and thus it is impossible to perform simultaneous recording by the Disc At Once recording method.
In addition, there is a problem as to recording speed resulting from variations in the disk type. The CD-RW discs have limited recording speeds. For example, there are a disc exclusively for double speed, a disc for a range of single to quadruple speeds, a disk for a range of quadruple to 12× speeds, and the like. When discs with different recording speed ranges are mixed, simultaneous recording by the Disc At Once recording method cannot be performed.
Accordingly, in order to perform simultaneous recording on the plural discs in the CD duplication system, a large number of discs with the same lead-in area start time and recording speed range should be prepared.
The present invention is made to solve the above-mentioned problems and has for its object to provide an optical disc recording control method and a drive for creating an optical disc that is reproducible even when an error occurs while data is recorded in a track of the optical disc and then the recording process is suspended, and an optical disc recording system which simultaneously performs recording on different types of optical discs.